TWEED Byron police have revealed they were on terror alert at the Splendour in the Grass music festival held over the weekend.

Superintendent Wayne Starling said officers were on "high alert for terrorism" and had been trained for terror confrontations in the lead up to the three-day event, in line with a NSW Police directive for mass public events.

More than 33,000 punters per day, including 17,500 campers, poured into the Splendour site at North Byron Parklands, located on the border of the Tweed and Byron shires at Yelgun.

Supt Starling said police were expected to be on terror watch at Splendour, and would continue to be on high alert at future festivals including Falls and Blues Fest, which are also held in the Tweed Byron Local Area Command.

"We are on high alert for terror in the NSW Police," Supt Starling said.

"The fact that we've had incidences in Australia that are terror related, we don't have the luxury of taking any chances, it means we have to be extra vigilant.

"We've had the Lindt siege, the public servant shot at Parramatta, we've had half a dozen other events that have been mitigated or ceased due to police interaction before they took place.

"We'll do anything in our power to ensure that everybody has a good time at the concerts and goes home safe to their family.

"Training is ongoing; wherever you have huge crowds that's always in the back of our minds and this will be ongoing."

Supt Starling said in addition to officers paid for by the promoters, the command

was expected to divert local resources to the festival's security needs.

"The festivals are challenges for us and we have three main festivals a year and as a result we have to re-deploy our police from frontline to policing to address those festivals," Supt Starling said.

Supt Starling's comments come as NSW Police praised the behaviour of festival-goers from Friday to Sunday, which included around 17,500 ticketholders camping on site.

A high visibility police operation at the sell-out event included 120 officers from Tweed and Richmond areas, in addition to 10 horses from the Public Order and Riot Squad as well as six dogs from the Dog Unit.

As a result of the drug dog operation, 323 people were detected in possession of prohibited drugs, including cannabis, 'ice', MDMA and cocaine.

Punters to lose their Splendour tickets, police warn

Police issued 80 cannabis cautions and more than 200 field court attendance notices.

Five people were charged over alleged drug supply, including a 20-year-old man who was intercepted by security for attempting to gain entry to the festival without a valid ticket.

While searching the man, police allegedly located MDMA as well as a restricted prescribed substance, all of which was seized and will undergo forensic examination.

The man was arrested and taken to Byron Bay Police Station where he was charged with possession of a prohibited drug and supply of a prohibited drug.

He was granted conditional bail and is due to face Byron Bay Local Court on Monday, August 15.

Police issued more than 50 criminal infringement notices over alleged trespassing offences after people were detected attempting to enter the event grounds without valid tickets.

There was also a licensing operation in place over the course of the festival, which detected 16 breaches of license conditions.

The alleged breaches will now be the subject of further investigation and possible legal action.

Supt Starling said he was pleased with the overall behaviour of festival-goers at this year's event.

"Once again, police worked closely with Splendour organisers to ensure a safe and enjoyable festival, so it was positive to see that the majority of attendees heeded police warnings and behaved themselves," he said.

"Our officers were even approached by music fans who thanked them for being there to keep everyone safe - it was tremendous to see such great support from the event community.

"Unfortunately, there were some who ignored our advice and attempted to bring prohibited drugs into the festival; however, they were quickly intercepted by our drug-detection dogs.

"We cannot reiterate enough how dangerous these substances can be; they are not only illegal but they can be incredibly harmful to your health and, tragically at times, fatal.

"We were not there to spoil the fun, but those who choose to break the law or threaten the safety of other festival goers will be stopped in their tracks and dealt with accordingly."